1. Field
The present disclosure relates to a singulated elastomeric electrical contactor for high performance interconnect systems and a method of the same. In particular, the present disclosure relates to a method and a system for replaceable elastomeric pins with a mechanism for locating and securing these pins within a housing.
2. The Related Prior Art
An electrical interconnect mechanism includes at least two electrically conductive contact pads, an electrically conductive path connecting such contact pads, a housing, a compressing structure, and some form of compliant, mechanically resistive mechanism that allows the pads to press against aligned electrical pads of two objects in need of electrical connection.
Three contact technologies are primarily used in the industry from prior art. The first uses a metal spring. While several variations exist for this type of contact technology in the electronics industry, the basic principle is this: a coiled or linear spring in the individual contactor compresses between two contact pads or regions. The spring provides the required force and mechanical hysteresis. As the dominant technology in the electronics industry, this method has the primary benefit of long life, excellent mechanical hysteresis, and the ability to replace individual contact mechanisms easily. This is also the most universal electrical contactor technology for high performance applications.
The second contact technology employs a small metallic rocker for pressing against a non-conductive polymeric elastomer of various durometers. The polymeric elastomer provides a required force and a mechanical hysteresis. When an object is pressed into the individual rocker, the rocker pushes back as one or more ends presses against the elastomeric spacer. This technology however is rather limited by the shape and type of object for which electrical contact is to be made. The main benefit of this technology is the long life of the contactors and the ease with which an individual contactor can be replaced.
The third type of mechanical contactor involves a polymeric elastomeric material filled with metal particles. While several varieties of this general class of contactor exist, all such conductive elastomers are formed in a sheet or a plane, and the individual contactors must be grouped together in a matrix. The primary benefit of the conductive elastomeric contactor is electrical performance—both contact resistance and very high frequency performance. In critical RF parameters elastomeric contactors out-perform equivalent metal contactors approximately 10:1 (self-inductance). However, individual pins cannot be replaced, as elastomers are built either on or in sheets. Another critical issue with the elastomer is lifetime degradation due to over-compression. A final problem is that in elastomeric sheets, individual contact points cannot act independent of one another, making the sheets difficult to use in applications where the connecting objects have poor co-planar properties.
It would be desirable to provide an electrical interconnect mechanism with the following key criteria:
First, a key criterion would be addressing the resistive force that presses against the objects in need of connection. While force is needed to maintain the connection, a high amount of force is required in mechanically complex structures in order to press the objects together.
Next, a compliance range is required to absorb the mechanically coplanar differences between the two objects.
A mechanical hysteresis is needed so that the aforementioned resistive force will return the contact pad to a nominal position after being compressed.
Another criterion is that of the physical size of the interconnect system, X-Y direction (often described as “pitch”).
Also important is the physical height of the interconnect system, Z direction, which most often relates to critical performance properties in very high speed, digital, and RF interconnect systems.
An electrical property known as “contact resistance” (CRES), which describes the degrading loss of energy to heat in the interconnect system is yet another criterion.
Long Lifetime of the interconnect system in its use environment is also important.
The ability to make the system configurable from just a few interconnects to several thousand is important as well.
Low cost and ease of replacing an individual interconnect mechanism when damaged or fatigued from use (end of life) is another important consideration or criterion.